01 - Preheat oven to 350°F. Grease a 12-cup mini muffin pan thoroughly with butter or cooking spray.
02 - In a medium bowl, whisk together flour and salt. Cut in cold butter using a pastry blender or two forks until mixture resembles coarse crumbs. Sprinkle cold water over the mixture, 1 tablespoon at a time, mixing gently with a fork until dough just holds together when pressed.
03 - Roll out dough on a lightly floured surface to 1/8-inch thickness. Cut twelve 3-inch circles using a round cookie cutter or glass. Gently press each circle into the wells of the mini muffin tin, pressing up the sides to form cups.
04 - In a separate bowl, whisk together brown sugar, corn syrup, melted butter, egg, vanilla, and salt until completely smooth. Fold in chopped pecans until evenly distributed.
05 - Spoon approximately 1 tablespoon of pecan filling into each prepared crust, filling about three-quarters full. The filling will expand slightly during baking.
06 - Bake for 22-25 minutes until filling is set and no longer jiggles in the center, and crust edges are golden brown. Watch closely during the last few minutes to prevent over-browning.
07 - Let pies cool in the pan for 10 minutes. Run a thin knife around the edges to loosen, then carefully remove to a wire rack. Cool completely before serving. Enjoy plain or topped with whipped cream.